Table 2 Identifier and details of studies which investigated the advantages of high-dose vitamin C in patients with COVID-19

NCT04401150

CT

R

Q

Arm 1: Vitamin C: 50 mg/kg of weight administered intravenously every 6 h for 96 h (16 doses)

Arm 2: Normal saline (0.9% NaCl) or dextrose 5% in water (D5W) in a volume to match the vitamin C

Death or persistent organ dysfunction

NCT04342728^*

CT

R

O/L

Arm 1: 8000 mg of ascorbic acid (daily with food)

Arm 2: 50 mg of zinc gluconate (daily)

Arm 3: 8000 mg of ascorbic acid and 50 mg of Zinc gluconate

Symptom Reduction in 28 days

NCT04357782

CT

N/R

O/L

Arm 1: 50 mg/kg l-ascorbic acid (every 6 h for 4 days) in the group with mild deoxygenation

Arm 2: 50 mg/kg l-ascorbic acid(every 6 h for 4 days) in the group with sever deoxygenation

1. Incidence of adverse events

2. Incidence of serious adverse reactions

3. Incidence of adverse reactions

NCT04323514

O

N/A

O/L

10 g of vitamin C intravenously in addition to conventional therapy

In-hospital mortality

NCT04344184^*

CT

R

Q

Arm 1: 100 mg/kg intravenous vitamin C infusion (every 8 h 3 days)

Arm 2: Dextrose 5% Water

Ventilator-free days

NCT04264533^*

CT

R

T

Arm 1: 50 ml injection: 12 g vitamin C + Water

(every 12 h for 7 days)

Arm 2: 50 ml of sterile water (every 12 h for 7 days)

Ventilation-free days

IRCT20190917044805N2^**

CT

R

D

Arm 1: 200 ml volume including 12,000 mg of vitamin C in dextrose 5% for 4 days

Arm 2: 200 ml of Distilled water in dextrose 5%

1. Time to clinical improvement (TTIC)

2. Time to clinical improvement (TTIC) of NEWS2 (National Early Warning Score 2)

IRCT20200324046850N5^**

CT

R

D

Arm 1: Main regime + 500 mg of vitamin C

Arm 2: Main regime + Placebo of vitamin C

Number of hospital admission days

IRCT20151228025732N52^**

CT

R

O/L

Arm 1: 2000 mg of vitamin C every 6 h for 7 days + main regime

Arm 2: Only the main regime

1. The rate of decline in lung infection rate

2. Number of breaths per minute

3. The course of the disease

4. Heart rate